Calendar.



WV G., PAIRGHILD CALENDAR.

APPLICATION FILED NOV.11,-1909.

Patented May 17, m0.

2 slums-sum 1.

ANDREW a. GRAHAM c0 PHGTO-UTIIOGRAPMERS. WASHINGTON, ac

W. G. FAIRGHILD.

CALENDAR.

APPLICATION FILED H0111, 1909.

958,1Q6 Patented May 17, 1910 2 SHEETS-SHEET 2.

WNTTF STATES PATNT FFTCE.

WILLIAM G FAIRGI-IILD, 0F SAVANNAH, GEORGIA.

CALENDAR.

To all whom it may concern:

Be it known that I, WVILLIAM G. FAIR- CHILD, a citizen of the United States, residing at Savannah, in the county of Chatham and State of Georgia, have invented certain new and useful Improvements in Calendars, of which the following is a specification, reference being had to the accompanying drawlngs.

This invention has relation to certain new and useful improvements in perpetual calendars of that character shown and described in Patent Number 534,628 dated February 26, 1895. 7

The primary object of the present invention is to simplify and materially increase the efficiency and facilitate the operation of a calendar of the type disclosed in said patent.

Another object of the invention is to provide means whereby the calendar month of any year in any century may be readily ascertained without requiring the application of a multiplicity of rules.

Another object is to provide means whereby the months of the old style calendar, in vogue prior to the year 1582, may be ob tained as well as those of the latter day or Gregorian calendar.

With these and other objects in view, the invention consists of the novel construction, combination and arrangement of parts, hereinafter fully described and claimed, and illustrated in the accompanying drawings in which,

Figure 1 is a plan view of my improved calendar. Fig. 2 is a section taken on the line 2-2 of Fig. 1, and Fig. 3 is a plan view of one of the month disks.

Referring to the drawings 5 indicates the primary member of my improved calendar which may be constructed of cardboard, celluloid or other material which may be found desirable. As shown, this member is of rectangular form and is centrally depressed as at 6 to receive a rotatable disk 7. By thus mounting the disk, the upper surface of the same is disposed in the same horizontal plane as the member 5. A pivot 8 extends through the center of the disk 7 and the primary member, and to the under side of the disk a knob 9 is secured, through which the pivot pin also extends. The knob is however, rotatable upon the pivot whereby the disk 7 may be readily rotated within the depressed portion of the member 5. Printed upon the Specification of Letters Patent.

Application filed November 11, 1909.

Patented May 17, 1919.

Serial No. 527,470.

member 5 beyond the edge of the disk 7 is the word Years. To the right of this word a cipher (0) appears. The numbers from 1 to 99 inclusive representing the years of a century are arranged below the word Years in consecutive order beginning at the right and reading downwardly. Three rows of twenty-eight numerals each are arranged in concentric relation to the disk 7, the fourth row of numerals comprising those from 85 to 99 inclusive, which completes the years of the century. The disk 7 has printed thereon contiguous to its edge the week day abbreviations which begin with Tuesday and are not arranged in consecutive order. The first of these week days is printed in red, as is every fourth day thereafter. As shown, the days Wednesday, Monday and Friday, are also printed opposite to the days Tuesday, Sunday and Thursday, which are printed in red. The disk also has printed thereon a circle and the word Centuries extends through the circumference of said circle at one point. Upon the outside portion of the disk or beyond this circle, and above the circular arrangement of days, the words New style are printed, while upon the inside of the circle are the words Old style. It will be observed that radial rows of numerals are provided opposite certain of the week days printed in red and having arranged on the same line therewith the days printed in black. Another row of century numerals is printed opposite the word Saturday, and to distinguish the same from those above mentioned these numerals are printed in red under the new style centuries. This provision is made to cover the first year of the centuries which are the leap years, as will hereinafter appear. Under old style centuries are arranged in radial relation to the week day abbreviations in red, the century numerals from 1 to 17 inclusive which are likewise printed in red. These numerals are only to be used in the operation of the calendar, when an old style century is under consideration, or before the Gregorian calendar advance which occurred in 1582 and was first accepted by the various Catholic countries. For the states of Germany and Denmark the old style century should be used before the year 1700, when they also accepted the Gregorian advance. For England, the old style century should be used for calculations before September 13, 1752, while in Russia the old style calendar is still in use to the present day. While I have shown in the drawing a calendar which includes from the first to the thirtieth century, it will be obvious that the same may be extended ad infim'zfum. In the arrangement of the numerals under new style centuries, it will be noted that they increase in the sequence of their respective radials by tours from the 15th to the 30th centuries, and in the extension of these centuries the same sequence of numerals is to be adhered to. Upon the opposite side of the disk the days of the week are printed contiguous to its edge and are arranged successively. These designations begin with Tuesday and end with Tuesday, though this arrangement is not essential to the operation of the calendar. Above the same the word Days is printed. The primary member 5 is provided with the elongated openings 12 and 12 which are arranged in spaced relation to each other and extend radially from the disk. Pivoted to the primary member by means of pins 13 are the month disks 1 1 and 15 which are disposed beneath the same and are adapted for rotative movement. These disks have printed thereon the twelve months of a year, and upon the side of each month nearest to the disk a numeral is printed, while upon the opposite side of the month designation the number of days in that particular month appears. The arrangement of the months upon the disk 14: are printed in black ink, while those on the other disk 15 are in red ink. Above the upper opening 12 the word Months is printed in large type, and the disks are each movable so that their monthly designations may be positioned and read through these openings. Upon the member 5 between the openings .the numerals of a complete calendar month are arranged in consecutive order, and below the lower opening 12 a second arrangement of such numerals is printed in red ink.

The manner of operating my improved calendar is substantially as follows: To obtain the calendar month for November 1912, the number 19 under the new style centuries is arranged by turning the disk 7 in radial alinement with the word Years The number 12 under Years is thus disposed opposite to the week day abbreviation for Monday on the adjacent edge 01? the disk. It will be noted that Monday appears in red ink. In such an event the month disk which is printed in red must be used. By the above operation the key day is found and this day applies to any month in the year 1912. After thus obtaining the key day, the same day Monday under Days is moved opposite to the opening 12, under which the months printed in red appear. The months disk 15 is then turned until November appears in the opening and it will be seen that to the left of November is the numeral 1, Thus in the year 1912 Monday isthe 4th of November. The central disk 7 is then turned to position the designation Monday in radial alinement with the numeral 4 printed in red under Months when the complete calendar month for November will be 0btained. Therefore Friday is the 1st of November in the year 1912, and the other days of said month may be read accordingly. If any other month in the year 1912 is desired, the month disk is turned until the same appears in the opening 12. Thus in June the 3rd fell on Monday, and the etth of March is also Monday. After obtaining the key day for any particular year, this day is applica ble to the various months of the year in obtaining the calendar month. By printing every fourth day in red under Centuries, the recurring leap years are provided for and all calculations obviated. When two days appear on the same radial of years, one printed in red and the other in black, the red day is used when the first year of a century is under consideration, and this arrangement is provided to cover the fact that though it may follow in its natural sequence of four it does not necessarily become a leap year unless divisible by four or its multiple without a remainder. This occurs only when the first year of a century is under consideration, the other centuries wherein the first year is a leap year being printed in red under New style as previously set forth. Then the calendar month desired occurs in a leap year, the key day of the same will be indicated bythe days printed in red in the key days. It necessarily follows that as the month of February in a leap year has 29 days whereas in other years there is only 28 days in this month, separate month disks must be provided. In order to distinguish between these disks they are printed in different colors and separate openings 12 and 12' are provided through which the months may be observed, but one month on each disk being visible through these openings. lVhen the calendar days of a month in a leap year are to be found as indicated by the red key day, the corresponding day under the table of week days on the opposite side of the disk is moved in alinement with the month printed in red on the disk 15. lVhen the key day is printed in black, the corresponding day under the week days is positioned opposite to the month of the disk 14 printed in black which appears through the opening 12. In this manner all liability of confusion arising is obviated, a separate month disk being provided for the ordinary years and the leap years.

As an illustration of the limits to which a calendar of this character may be put, we will obtain the calendar month for July 2371. The operation is precisely the same as above described and the numeral 23 under New style century is moved by rotating the disk into radial alinement with the word Years, when 74: under Years will appear opposite Tuesday. As Tuesday ap pears in black, Tuesday under Days is moved opposite to the opening 12 through which the months are read also printed in black. The disk 14; is then rotated to position July beneath the opening when it will be observed that the 2nd of July is Tuesday in the year 2374. The disk 7 is rotated to move Tuesday opposite to the numeral 2 of the month numbers printed in black, when the entire calendar month for July of the year desired is obtained.

From the foregoing it is believed that the operation and many advantages of my improved calendar will be clearly obvious wit-hout requiring a more extended description. Its main point of advantage over all other calendars of a similar character is that the multiplicity of rules required in their operation have been entirely eliminated, but one rule being required in the operation of the present invention, and that is to find the key day for any given year, apply that day to any month in that year and its calendar is obtained. Its simplicity is such that it may be very quickly operated without requiring any calculations whatever, the months throughout the entire range of years from the beginning to the end of time being always and almost instantaneously obtainable.

The principle involved in the construction and operation of the calendar resides in the fact that once in every twenty-eight years, time repeats itself. By closely observing the construction and manner of operation of the calendar this will be at once apparent and the simplicity of the mathematical conclusion involved therein will be readily distinguished.

While I have shown and described the particular arrangement of the various rotating disks carried by the primary member, it will be obvious that they may be mounted or arranged in any other desired manner whereby the same results are obtained, without materially departing from the essential features or sacrificing any of the advantages of my invention as claimed.

Having thus described the invention what is claimed is:

1. The herein described calendar compris ing a base member, a disk rotatably mounted centrally upon said base member, said disk having a plurality of key days designated thereon adjacent to its periphery, means for finding the key day of any year of any century, a second peripheral table of days opposite said key days, a rotatable disk mounted on said base having the months of the year designated thereon, the number of days in the month and one of the calendar days being indicated on either side of each month, the day in said second table of days on the central disk corresponding with the key day being adapted to be moved into radial alinement with a particular one of the months carried by the month disk, and calendar month numerals printed upon said base, the week day in the last named table of days being adapted to be moved opposite the numeral in said calendar corresponding to the calendar number appearing opposite to the month on said month disk whereby the calendar day of the key day will be indicated, substantially as and for the purpose set forth.

2. The herein described calendar comprising a base member, a rotatable disk centrally arranged therein flush with the surface of the base member, key days designated on said disk adjacent to its periphery, means for finding the key day of any year of any century, a table of week days arranged in consecutive order contiguous to the periphery of the disk opposite the key days, two disks rotatably mounted on said base each having the months of the year printed thereon and the number of days in the months and one of said days indicated opposite each month, said disks being printed in distinctive colors to indicate ordinary and leap years, the day in the last named table of days corresponding with the key day being adapted to be moved to the particular month desired on one of said disks, the numerals of the complete calendar month being printed upon the base, the calendar numeral opposite said month indicating the calendar day of the week day, said week day being adapted to be then moved into alinement with the corresponding numeral in the monthly calendar whereby the calendar month for the year desired is ascertained.

3. The herein described calendar comprising a base member, a disk rotatably mounted on said base member flush with the surface thereof, a table of key days indicated on said disk, means for finding the key day of any year, a second table of days arranged in consecutive order contiguous to the periphery of the disk opposite the key days, said base having openings therein extending radially beyond the periphery of the disk, disks arranged upon said base beneath said openings, said disks each having designated thereon the months of an entire year, the number of days and the numeral indicating one of the days appearing upon each side of each month, said disks being printed in distinctive colors, each of the months thereon being successively movable beneath the openings in the base, the day in said last named table of days on the first named disk corresponding with the key day being adapted to be moved into radial alinement with a particular one of the months on said disks, the

numerals of two calendar months being the year may be obtained, and means for 10 printed upon said base in colors correspond rotating said disks.

ing to the disks, the .key day in the last In testimony whereof I hereunto affix my named table of days being adapted to be signature in the presence of Witnesses.

then moved opposite to the numeral in one WILLIAM Gr. FAIROHILD. of said calendar months on the base corre- \Vitnesses:

sponding to the calendar numeral opposite EDWARD SHAW,

the month appearing in the opening in the JAMES EVANS,

base, whereby the entire calendar month for F. H. FERGUSON. 

